1. Field of the Invention
This invention relates to a combined hull and steering mechanism for marine vessels and particularly for a special purpose marine vessel that is commonly used to move work barges and other similar craft required for the construction of piers, docks and other marine structures, this craft being referred to in the maritime trade as a “pushboat”.
2. Description of the Related Art
Pushboats are essential vessels required in the construction of piers, docks and the like. A pushboat must be highly maneuverable and must be able to move other large marine vessels, such as barges, in the typically tight surroundings of a construction project. Pushboats are relatively small and manned by a single operator.
Pushboats have been used on the aforementioned types of jobs for many years. The name pushboat is derived from a large flat vertical plate that extends across the bow, which can make stable contact with the flat side hull of a barge, floating dock or the like, to provide a broader area of contact, and therefore stability during the maneuvering operation. The distinctive feature of the pushboat is its flat bow surface or prow, which distinguishes it from a tug boat and other work boats that have a more traditional hydrodynamically tapered or pointed bow that is more efficient for forward movement.
One problem with pushboats, however, is the fact that the flat bow plate limits maneuverability of the boat through water as there is a significant amount of lateral resistance encountered when such a vessel is turned. Typically, additional rudders known as flanking rudders, are required to aide in the steering of pushboats to compensate for this lack of maneuverability. They are positioned outboard and forward of the propeller
One object of the present invention is to provide a marine vessel which is less resistant to lateral forces of the water when turning and thus has much greater maneuverability and is faster than other marine vessels of similar shape and size.
Another object of the present invention is to provide a marine vessel having a hull that is configured to allow the vessel to turn in a tighter pattern and to move more efficiently than other marine vessels of similar size and function.
Still another object of the present invention is to provide a marine vessel which is capable of coming about 180 degrees, and even of turning 360 degrees, in its own length.